Tilting mechanism for venetian blinds



Patentecl Feb, 6, 1945 'TILTING MECHANISM FOR VENETIAN BLINDS Edward E.Schaefer, Oak Park, Ill.

Application August 26, 1944, Serial No. 551,276

13 Claims.

This invention relates to Venetian blinds and more particularly to animproved mechanism for tilting the slats oi Venetian blinds in order tocontrol the amount of light passing therethrough. The improved tiltingmechanism is adapted for application at the top of a blind of well-knownconstruction in which the slats are supported by ladder tapes secured tothe tilt bar or head rail. The tilting mechanism is operably connectedto the tilt bar and operation of the improved mechanism, having a novelconstruction to be described hereinafter, by means of depending cordsaccessible to the operator, causes tilting of the tilt bar andconsequent tilting of all the slats therebelow.

In tilting mechanisms of this character, the operating cord, havingdepending loose ends, extends over a pulley wheel which may be rotatedone way or the other by pulling down on one or the other ends of thecord was to efiect tilting of the slats through the other elements ofthe mechanism. When the tilt bar and slats are in horizontal position,it is desirable that the cord lengths on either side of the pulley beequal so as to permit operation of the tilting mechanism and consequenttilting of the slats throughout their full range. However, a longrecognized dimculty inherent in such tilting mechanisms is the tendencyof the operating cord to slip relative to the' pulley during operationso that, after a period of operation, the lengths of cord become uneven,

one long and one short. This inequality of length not only prevents fulltilting movementwhen the knob on the short end catches on the pulley,but also causes the short end to be in such an elevated position that itis out of the ordinary reach of the operator.

Attempts have been made to overcome this undesirable tendency byproviding a positive nonslipping drive connection between the operatingcord and the pulley. Still other attempts have accepted the inherenttendency of ,cord to slip somewhat about the pulley and sought toprovide a mechanism for readjustment ofthe cord ends to equal lengthwithout requiring the entire disassembly of the tilting mechanism.Generally, the results of these attempts have been relativelyunsuccessful, not only from the standpoint of the results achieved butalso with respect to the expensiveness and complexity of, the mechanicalstructures devised.

In e such attempt, a structure has been provided n which the pulley wasadapted to be operably disconnected from the remainder of the tiltingmechanism by pulling the cord ends outwardly or away from the blind. Insuch outward position, the cords were, then adjusted to equal length,the pulley being free to rotate during adjustment without eifectingoperation of the remainder of the tilting mechanism. However,

ill

in making such an adjustment of the cords in the mechanism of theforegoing character, it was necessary to keep the cord lengths underrelatively high tension to maintain the pulley in disconnectedcondition; and, because of this fact and because the pull of theoperator was necessarily outwardly away from the blind, the blindmountings were put under extraordinary stress in a direction whichtended to loosen and weaken them to the breaking point. Also, because ofthe unnatural direction at which the operator was required to pull thecords, the various parts of the mechanism were placed under anundesirable strain which sometimes caused their deformation and failureto return to normal position upon release of the cords by the operator.This failure to resume operable position thus resulted in completefailure of the tilting mechanism and necessitated disassembly andreformation of the parts.

However, by means of the structureembodying the present invention, thedisconnection of the pulley from operable engagement with the'tiltingmechanism is accomplished by the operator simply by holding the cordstaut and moving their ends upwardly in either direction in a slight arcand in "a plane substantially parallel to the mountings or upon thevarious parts of the tilting 'mechanism itself. rThe pulley is thereforeadapted to be readily disconnected from driving engagement by a simpleswinging movement of the cord ends and the cord lengths are capable ofbeing equalized when under a very slight tension sufflcient only to keepthe cord lengths taut during adjustment.

It is, therefore, one of the objects of my invention to provide animproved slat tilting mechanism" for a Venetian blind comprising partswhich may be operably disconnected from the remainder thereof for cordadjustment by movement of the operating cords in a circumferentialdirection about the tilting mechanism and in a plane substantiallyparallel to the plane of the blind.

Another object of my invention is the'provision of an improved slattilting mechanism by which the pulley thereof may be operablydisconnected proved slat tilting mechanism 'of a simple and inexpensiveconstruction and having a pulley wheel which may be operablydisconnected from I the tilting mechanismby a simple and effortlessswinging movement of the cord ends in a plane substantially parallel tothe plane of the blind.

' Still another object is the provision of a slat a simple and eflicientmeans for permitting equalizing adjustment of the operating cords andbeing capable of a long operable life.

Other and further objects of my invention will become apparenthereinafter as this description progresses, reference being had to theaccompanying drawing, in which:

Figure 1 is aperspective view of the various component parts of theimproved tilting mechanism comprising my invention in relativedisassembled or exploded relationy Fig. 2 is a side elevational view ofthe improved tilting mechanism illustrating the pulley and other partsin operable driving connection for slat adjustment; I

Fig. 3 is a rear elevational view of the tilting mechanism, as viewedfrom the'rlght in Fig. 2, and showing in broken lines the angularposition assumed by the cord guide member during cord adjustment; and

Fig. 4 is a side elevational view of the tilting mechanism showing theparts in their operably disconnected position during cord adjustment.

The improved slat tilting mechanism comprising my invention and shown inFigs. 1 to 4, inclusive, of the drawings, is adapted to be applied to aVenetian blind of the usual construction in the slats therebelow iseffected. This tilting movement of the tilt bar is accomplished by meansof the improved tilting mechanism comprising my invention which will nowbe described.

Referring to the drawing, the tilting mechanism comprises a housing orbracket member ID composed of two complemental semi-oval sections Handl2 which are adaptedto be secured together, upon insertion-of certainmechanism therewithin, by means of rivets l3. The sections II and I2 areeach provided at their upper ends with laterally directed flanges I 4and I5 having holes I to and lid through which screws (not shown) maybe'inserted for securing the entiretilting unit to the main supportingbar of a blind. The housing H) is further provided with a transverselyextending cylindrical cavity I! which is further enlarged, at its innercentral portion Hi to accommodate a worm gear l9. The worm gear IS-maybe integrally formed with a rotatable shaft 23 which is supported withinthe cavity ll of the housing Ill but projects outwardly therefrom at itsleft end. That portion of shaft 20 which extends within the housing Inis circular while the portion thereof which A worm wheel 23 is journaledin an opening.

24 in the lower part of the housing I 0 and extends radially andupwardlywithin the housing into meshing engagement with the worm gear IS. Theworm wheel 23 is provided at its central portion with a square aperture26 which is adapted to receive a boss (not shown) of square crosssection operably connecting the worm wheel 23 to the tilt bar. By theforegoing construction, rotative movement of the shaft 20 causes tiltingmovement of the head rail and consequent tilting of the slats, throughthe worm gear l9, worm wheel 23, and the tilt bar (not shown).

On the reduced circular end portion 22 of the rotatable shaft 20 is apulley 21 supported thereon for free and independent rotative movementrelative thereto. The pulley 2lmay be of the usual construction and isoperable by a single cord 28 which extends over the top of the pulleyand depends on either side thereof. Downward movement of one or theother of the loose ends is threadedly received within a threaded bore inthe end of the circular portion 22 of shaft 20. On the inner verticalface of the pulley 21 and in concentric relation to a round aperture 29therein through which. the shaft portion 22 extends, there is fixedlysecured a driving clutch member in the form of a collar or shortcylinder 30 which has a circular outer contour and an hexagonal innercontour as at 3|.

A gulde member 32 is supported by the pulley 21 for free and independentrelative rotative or rockable movement by mean of an upstanding circularwall 33 at its right side, this wall 33 being provided with a centralaperture into which is received the diving clutch collar 30 of thepulley 21. An annular washer 36, composed of a suitable lubricatingmetal, is carried by the collar 30 and is, therefore, interposed betweenthe inner face of the vertical wall 33 of the guide member 32 and thepulley 21 to insure easy and free relative rotative movementtherebetween.

The lower end of the guide member 32 is pro-,

vided with a restricted opening 25 through which the operating cord 28extends downwardly from the pulley to a point accessible to theoperator.

Secured to the outer face of the wall 33 of 391), respectively, and withdiametrically opposite vertical faces 38c and 390 at their other ends.The camways 38 and 39 are adapted to cooperate with a pair of axiallyextending tongues 4| and 42 integrally formed in diametrically oppositerelation at the outer extremities of a plate member 43. The tongues 4|and'42 in normal slat tilting position are adapted to engage the outerface portions of the wall 33 of the guide member 32 between the arcuatecam members 38 and 39, as shown in Figs. 2 and 3 of the drawing. Inmoving from normal position to cord adjusting position, the tongues areadapted to ride up the inclined cam faces 38a and 39a of the cam membersand engage the raised outer flat surfaces 381) and 39!), as will be morefully described hereinafter.

The plate member 43 is supported on the hexagonal portion 2| of theshaft 20 by means of a driven clutch member 44 secured within a centralopening 45 of the plate member 43. The

driven clutch member 44 is provided with an: hexagonal head 46 which isof larger size than the diameter of the opening 45 of the plate mem-.ber but of theproper size and shape for recep-' tion within thehexagonal opening 3| of the driven clutch member 30. The driven clutchmember 44 is provided with an axially extending annular portion 44awhich is adapted to be inserted through the opening 45 of the platemember 43 and secured therein by swaging the outer edges thereof to forma retaining collar 48. By this construction, although the plate member43 is confined against axial movement relative to the driven clutchmember 44, it nevertheless is unaffected by rotative movement of thatclutch member which turns freely within its opening 45.

The driven clutch member 44 is carried on the hexagonal portion 2| ofthe shaft 20 for rotative movement therewith and transmits rotativemovement from the pulley 21 and the driving clutch member o the shaft20. The clutch member 44 and the platemember 43, which are adapted toslide axially along the hexagonal shaft portion 2|, are maintained intheir normal position at the left end of the hexagonal shaft portion 2|,as shown in Fig. 2, by means of ahelical spring 49 encircling the shaftportion 2| and compressed between the housing In and the swaged collar48 of the driven clutch member 44.

Although the plate member 43 is mounted on the driven clutch member 44sothat that clutch member may be free to rotate in its opening 45, anytendency of the plate member 43 to rotate with the driven clutch member44 due to inadvertent binding between the parts is prevented by means oftongues 5| and 52 which extend in an axial direction from the platemember 43 into engagement with the opposite sides of the housing I0.These tongues 5| and 52 may be integrally formed with the plate member43.

With the above-described parts in assembled condition asshown in Figs. 2and 3, the slats of the Venetian blind may be either opened or closedsimply by pulling down one or the other of the loose ends of the cord 28was to cause rotation of the pulley2l. Rotation of the pulley 21 causesrotation of the clutch member 30, which in turn causes rotation of theclutch member 44 and the shaft 20. As above described in detail,rotation of the shaft 20 effects rotation of the slats through the wormgear I! and the worm wheel 23. During this rotative'movement of theabovenamed parts, the cord guide member 32 and the plate member 43remain stationary, as above described.

If, after a period of usage, the lengths of the cord 28 below the pulleybecome excessively uneven due to slippage through the pulley and it isdesired to re-establish them to equal lengths, the operator may grip andhold taut the loose ends of the cord 28 and with a swinging motion withthe tilting unit as a center move them through an arc of 45 to 90 in aplane substantially parallel to the plane of the blind. This arcuatemovement may be either to the right or left, hence in either direction,depending upon the arrangement and disposition of the cam surfaces. Ineither direction, the arcuate movement is still in substantially thesame plane as the plane of the blind. During this movement the cordsengage the lower edges of the cord guide member 32 and cause it torotate or rock about the exterior annular surface of the driven clutchmember 30 to a position illustrated in Fig. 4 and indicated by thebroken lines in Fig. 3. As the guide member 32 turns about its pivot,the arouate carm members 38 and 39 are carried with it and movecircumferentially or clockwise as viewed in Fig. 2 so as to engage thetongues 4| and-42 and force them up the inclined cam surfaces 38a and39a to the high points 38b and 39b of the cam members. This latter ordeclutched position is illustrated in Fig. 4 of the drawing.

As thegtongues 4| and 42 are forced laterally to the high points 38b and39b of the cams 38 and 39, the plate member 43 is forced to the right asviewed in Fig. 4 so as to compress the spring 49 and retract the drivenclutch member 44 from engagement with the driving clutch member 30. Withthe clutch members 30 and 44 out of engagement, the pulley may be freelyrotated as the cords are equalized by the operator without causingrotative movement of the other parts. cord 28, the operator may graspeach cord and pull angularly downwardly on the shorter one until theloose ends are of the same length.

I From the foregoing description of the structure and mode of operationof the improved slat tilting mechanism comprising my invention, it

will be seen that the adjustment of the operating cord to equal lengthsmay be accomplished with minimum effort by the operator and without anyabnormal stress or strain being placed upon the operating parts of thetilting device. By a slight simple movement of the cords over arelatively short are which causes a simple pivotal movement of the guidemembers, the pulley is released from driving engagement and may berotated in either direction for cord adjustment. The parts of thetilting device are capable of being positively connected anddisconnected by the simple rocking or pivotal movement of one part. Thevery slight force applied by the operator to the cords is sulhcient onlyto keep the cords taut and therefore places the parts under no abnormalstrain, .nor is this negligible force applied in a direction tending topull the blind from its main supports. The tilting mechanism is,therefore, capable of operation over a long period of time withoutrequiring adjustment or repair.

Although by the foregoing description and in the accompanying drawingthere is set forth and illustrated one form of my invention, it is to beunderstood that changes and modifications may be made without departingfrom the scope of my invention as defined I claim:

1. A tiltin mechanism for a Venetian blind comprising a pulley, anoperating cord operably engaging said pulley. tilting means adapted tobe operatedupon rotation of said pulley, means for operably connectingsaid pulley and said tilting means. and means for operably disconnectingsaid pulley from said tilting means upon move- To equalize the looseends of the by the appended claims.

1 4 3 ment of the cord about the tilting mechanism as a. centerin.aplane substantially parallel with the plane of the blind.

2. A tilting mechanism for a comprising a pulley,-an operating cordextending over said pulley, tilting means adapted to be operated uponrotation of said pulley, clutch means operably connecting said pulleyand said tilting means, and means for rendering said clutch meansinoperative upon movement of the cord about the tilting mechanismas acenter in Y a plane substantially parallel with the plane of j the'blind.

3. A tilting mechanism for a Venetianblind comprising a rotatable shaft,a pulley supported by the shaft, an operating cord operably engagingsaidulley,.clutch means operably connect- I ing said rotatable shaftwith said pulley, and

disengaging said connecting means upon an arcuate movement of said cordin a plane substantially parallel to the plane of the 'blind.

5. A tilting mechanism for a Venetian blind comprising a rotatableshaft, a pulley supported by the shaft, an operating cord extending oversaid pulley, clutch means operably connecting said rotatable shaft withsaid pulley, and cam 1 means operable upon arcuate movement of said cordin a plane substantially parallel to the plane of the blind fordisengaging said clutch means.

6. A tilting mechanism for a Venetian blind comprising a rotatableshaft, a pulley supported by the shaft, an operating cord extending oversaid pulley, clutch means operably connecting I said rotatable shaftwith said pulley and adapted to be moved longitudinally of the shaftinto and out of operable clutching engagement, and cam.

means operable upon arcuate movement of said cord in a planesubstantially parallel to the plane of the blind for moving said clutchmeans longitudinally of the shaft to render said clutch 1 meansinoperative.

7. A tilting mechanism for a Venetian blind comprising a pulley, arotatable shaft supporting said pulley for free rotatable movementthereon, an operating'cord extending over said pulley, a driving clutchmember operably connected with said pulley, a driven clutch membercarried 'by said rotatable shaft and adapted for rotatable movement with-said shaft and for in- Venetian blind operable upon arcuate movement ofsaid cord in a plane substantially parallel to. the plane of the blindfor moving-said driven clutch member axiall along the rotatable shaftout of operable nectedwith said pulley, a driven clutch member carriedby said rotatable shaft and adapted for rotatable movement with saidshaft and for in dependent movement axially of said shaft, and meansoperable upon arcuate movementof said cord in a plane substantiallyparallel to the plane of the blind for moving said driven clutchmemberaxially along the rotatable shaft out of operable engagement withthe driving clutch about said shaft upon arcuate movement of said cordin a plane substantially parallel to the plane of the blind, and cammeans operable upon pivotalmovement of said rockable member for movingsaid driven clutch member axially along the rotatable shaft out ofoperable engagement with the driving clutch member.

11. A tilting mechanism for a Venetian blind comprising a pulley, anoperating cord operably engaging said pulley, tilting means adapted tobe operated upon rotation of said pulley, means for operablyconnecting'said pulley and said tilting means, a rockable member adaptedfor pivotal movement relative to said tilting means upon arcuatemovement of said cord in a plane substantially parallel to the plane ofthe blind, and

dependent movement axially of said shaft, means for urging said drivenclutch member into operative engagement with said driving clutch member,and cam means operable upon arcuate movement of said cord in a planesubstantially parallel to the plane of the blind for moving-said drivenclutch member axially along the rotatable shaft out of operableengagement with the driving clutch-member.

8. A tilting mechanism for a Venetian blind 1 comprising a pulley, arotatable shaft supporting said pulley for free rotatable movementthereon, an operating cord extending over said pulley, a

driving clutch'member operably connected with 1 said pulley, a drivenclutch member carried by means for operably disconnecting said pulleyfrom said tilting means upon pivotal movement of said rockable member.

12. A tilting mechanism for a Venetian blind comprising a pulley, anoperating cord operably engaging said pulley, a rotatable shaftsupporting said pulley, a rockable member supported by said shaft forpivotal movement independent thereof and adapted to be moved pivotallyabout saidshaft upon arcuate movement of said cord in a planesubstantially parallel to the plane of the blind, and means for operablydisconnecting said pulley from said tiltin'g means upon pivotal movementof said rockable member.

13. A tilting mechanism for a Venetian blind comprising a pulley, anoperating cord extending over said pulley, a rotatable shaft supportingsaid pulley, clutch means operably connecting said pulley and saidrotatable shaft and movable axially of said shaft, a rockable'membersupported .by said shaft for pivotal movement independent thereof andadapted to be rocked pivotally about said shaft by said cord, and cammeans adapted. to move said clutch means axially of said shaft uponpivotal movement of said rockable member to operably disconnect saidpulley and said shaft.

EDWARD E. SCHAEFER.

